Apparatus for obtaining a constant voltage



June 24, 1924. I 1,499,078

' F. SCHROTER APPARATUS FOR OBTAINING A CONSTANT VOLTAGE Filed March 16. 1921 Patented June 24, 1924.

UNITED STATES? 1,499,073 PTA-TENT OFFlCEr rarrz seasons, on BERLIN, enmanx-hssronoa 'ro SAFETY can HEATING a HLIGHTING COMPANY, A coaronarron or NEW JERSEY.

APPARATUS FOR OBTAINING A CQNSTANT VOLTAGE.

- Application filed March 16, 1921. Serial No. 452,824.

To all whom it may concern:

Be itknown that I, Fnrrz Sonatina, a citizen of the German Republic, and a resident of Berlin, Germany, have invented an Improvement in Apparatus for'Obtaining a Constant Voltage (for which I have filed an application in Germany Nov. '10, 1917, Patent No. 323,7 99), of which the following is a specification.

This invention relates generally to means for obtaining a constant voltage from an electric circuit subject to voltage or current fluctuations and more particularly to a gaseous conduction device for obtaining a constant volta e.

One of t objects ofthis invention is to provide a simple, compact and effective device for obtaining a constant voltage or fractional voltage from a circuit whose voltage is s'ubject to fluctuations or the current flow of which iss'ubject to material variations.

Another object of this invention is to provide a gaseous discharge tube of such characteristics that will permit it to function to maintain a substantially constant voltage at its terminals irrespective, of material variations in current flowing therethrough.

Other obj cts will be in part obvious or in Y part pointed out hereinafter.

The invention accordingly consists in the features of construction, combinations of elements and arrangementof parts, as will be exemplified inthe structure hereinafter described and shown in the accompanying drawing, and the scope of the application of which will be indicated in the following claims:

In the drawin the single -,figure repre 40 ment of this invention. 4

In the drawing the conductors 10 and 11 represent an electric circuit, the potential of which is subject to fluctuations and from which it is desired to obtain a substantially constant voltage which may be a substantial fraction of the total voltage of the circuit 10 and 11. Across the circuit 10 and ll there is connected through a suitable current tube comprising a vessel or container 13 of suitable material, which may be glass, for example, and the electrodes 14 and 15 mounted therein and connected respectively to the conductor 10 and resistance 12.

sents diagrammatically a preferred embodi limiting resistance 12 a gaseous discharge The vessel 13 contains a rarefied'atmosphere of a gas of the helium roup or of a mixture of several gases 0 this .group within which the electrodes 1 1 and 15 are adapted to operate and maintain a gaseous discharge therebe'tween. The electrode .15,

forming preferably the anode, may take the form, for example, of a cylindrical member either solid or in sheet form, of relatively small cross section and positioned centrally within the substantially cylindrical vessel 13. The cathode 1 1 may conveniently be made to take the form of a hollow cylinder substantially surrounding the anode 15, the anode '15 and the cathode 14 being provided with suitable conductors to connect them electrically to suitable terminals 17 and 16 respectively exterior of the vessel 13.

The electrodes 1 1 and 15 may be made of i any suitable metal or alloy but the cathode 14 is preferably made of a metal havin a relatively small cathode drop in potential. Metals of the alkali grou ,for example, are

characterized by a relatively lowdrop in potential when employed particularly as cathodes in gaseous discharge tubes of this type and electrodes 14 and 15 may conveniently be made of metals of this group or of alloys containing vmetals of the alkali group. When they material of the electrodes is chosen as above mentioned and when the gaseous content of the vessel 13 is chosen to be of a gas of'the helium group or mixtures thereof, the discharge tube may be given a voltage-current characteristic which will have'a substantial portion thereof substantially parallel to the current axis, having due regard for the pressure of the gas within the tube and for the size and arrangement of the electrodes. The portion of the characteristic selected for operation in the embodiment of this invention is that portion preferably relatively low pressures, a volt age-current characteristic of the abovementioned character is obtained and the portion correspondin to relatively small or substantially no anges in voltage to material changes in current therethrough results from the generation of ions or current carriers from the molecules of the gase ous content by collision of the ions already in existence with the molecules of the gas. 'I-Ience,the added number of ions in the aseous content necessary to carry the adde or increased current due to an increase in the voltage of the main circuit represented by the conductors 10 and 11 are obtained by collision, as hereinbefore described, without necessitating an increase in the potential across the electrodes otherwise r uisite to generate additional ions, the adde current being carried by additional ions generated by t e collision of the molecules of the gas with the ions already traveling at a high velocity from one electrode to another.

This action while diflicult of exact analysis, may be substantially that wlich takes place during that part of the cha c istic of the discharge tube at which the latter is operated in car ing out the objects of thisinvention.

In t e embodiment of this invention as illustratively shown in the drawing, a sub-' stantial change in voltage across the conductors '10 and 11 forming the electric circuit will cause a substantially proportional change in current through the tube 13 and through the resistance 12 in series therewith. Since, however, the tube has a voltage-current characteristic of the character above described and since the tube operates upon a selected portion of the characteris tic as above pointed out, substantial chan es in eurrent through the tube 13 resultmg om' the changes in voltage between the conductors 10 and 11 will cause substantially no change in potential across the terminals 16 and 17 of the tube 13, the characteristiclcurve of the tube" being substantially parallel to the current axls. Hence circuitsin which the voltage is desired to be maintained constant may be connected to the terminals16 and 17 of the discharge tube and may thus be derived from a circuit l uch as 10 and 11 in which the voltage is bject to substantiallywide variations;

It may also be noted that the conductors and 11 may constitute part of a series ircuit in which the current may vary maerially, and that a substantially constant lvoltageat terminals 16-17 may be derived from such acircuit subject to material cur- 60 rent fluctuations.

It will. be understood that the resistance 12 inseries with the discharge tube 13 functions tofilimit thtfcurrent passin through thetube, 13 and permits the app cation of full circuit voltage directly to the electrodes 14 and I 15 to insure the automatic \starting of the discharge between electrodes and thereafter functions as a protective resistance to the tube 13. v 1

11' order to obtain a smaller, constant voltage than is maintained at the terminals 16 and 17 of the discharge tube 13, a suitable relatively high resistance'18 is connected across the terminals 16 and 17 and is provided, with variable taps, 19-20, from which any desired fractionof the volta e acrossthe terminals 16 and 17 may be 0%1- tained. I

It will be notedthat there has been provided in this invention a simple'and effective means for obtaininga substantially constant voltage from a circuit whose voltage or current may be subject to material variations and that the several objects here-' inbefore inted out, aswell as others, have been attained.

As many possible embodiments may. be made of the above invention and as various changes might be made in the embodiment above set forth, it is to be understood that all matter as hereinbefore set forth is to be interpreted as illustrative and not in a limiting sense.

I claim as my invention:

1. In a device for'obt'aining a constant voltage, in combination, a main electric circuit subject to variations in voltage, and means connected to said circuit responsive to current changes due to said voltage fluctuations in said circuit, said means containing an electronic conduction path having the inherentcharacteristic of becoming conductive upon the application of the circuit voltage thereto and adapted to maintain a substantially constant voltage across the terminals thereof through said current changes.

2. In a device for obtaining a constant voltage, in combination, a main electric circuit subject to variations in voltage, means 11. connected in said circuit responsive to current changes due to said voltage fluctuations in said main circuit, said means containing a gaseous conduction path having the inherent characteristic of becoming conductive Ill upon the application of the circuit voltage thereto and including at least one gas of the helium group whereby an increase in the current therethrough is facilitated by the generation of ions by collision without an 18 increase in the potential across said means, and a resistance element connected in series with said means for absorbing the increase in voltage across said means and said resistance element.

3. In a device for obtaining a constant voltage, in combination, a main electric circuit subject to variations in current and comprising a resistance element and a gaseous conduction device in series with one an- 1' ing a rise in the potential across said device,'

and said resistance element functioning to hold the current within a predetermined maximum. I

4. In a device for obtaining a constant voltage, in combination, a main electric circuitsubject to variations in current and in-. eluding a gaseous conduction device having an atmosphere containing at least one gas of the helium group, said device being adapted to maintain a substantially constant voltage at its terminalsvand facilitating the passage of increases in current therethrough by increases in the electronic content by collision of ions already in existence with molecules of the gas without increasing the potential diiference at the terminals thereof, said device having the inherent characteristic of becomingconductive upon the application thereto of the circuit voltage.

5. In a device for obtaining aconstant voltage, in combination, a main electric circuit subject to variations in voltage, means connected to said circuit responsive to current changes due to said voltage fluctuations in said main circuit, and a resistance element connected in series with said means,

said means having a gaseous conduction ath composed of at least one gas of the elium group and having the inherent characteristic of becoming conductive upon the.

application thereto of the voltage of said ,main electric circuit, the electronic content thereof being adapted to be increased by collision of the molecules thereof with ions already existent in the path to facilitate the passage of increases in current therethrough without increasing the potential drop across said means, and said resistance element being adaptedv to absorb increases in potential 7 across said main circuit.

6. In a device for obtaining a constant voltage, in combination, a main electric'circuit subject-to variations in voltage, means connected to said circuit having a gaseous conduction path including at least one gas of the helium group and having the inherent characteristic of becoming conductive upon the application thereto of the voltage of said 'main electric circuit and adaptedto facilitate the passage of an increased current therethrou'h by increasing the number of electrons t erein by collision of the molecules of said gas with ions alreadyin existence therein and without increasing the potential drop across said device, a resistance element connected in series with said means and adapted to absorb increases-in the v ing voltage of said main circuit, a relative y high resistance; connected in parallel with said means adapted to be subjected by said means to a substantially constant IR drop, and means adjustably connected to said relatively high resistance adapted to select therefrom fractional portion of said substantially constant IR drop.

In testimony whereof, I have si ned my name to this specification this 22n day of 

